War in Korea, an Early WarKorean War, conflict between the Democratic People's Republic of Korea (North Korea) and the Republic of Korea (South Korea) in which at least 2.5 million persons lost their lives. The war reached international proportions in June 1950 when North Korea, supplied and advised by the Soviet Union, invaded the South. The United Nations, with the United States as the principal participant, joined the war on the side of the South Koreans, and the People's Republic of China came to North Korea's aid. The book on War in Korea, an Early War will give you the full detail.